Temperature Dependent Electronic Structure in a Higher Order Topological Insulator Candidate EuIn$_2$As$_2$

Sabin Regmi; Md Mofazzel Hosen; Barun Ghosh; Bahadur Singh; Gyanendra Dhakal; Christopher Sims; Baokai Wang; Firoza Kabir; Klauss Dimitri; Yangyang Liu; Amit Agarwal; Hsin Lin; Dariusz Kaczorowski; Arun Bansil; Madhab Neupane

doi:10.1103/physrevb.102.165153

arXiv · 1911.03703

Temperature Dependent Electronic Structure in a Higher Order Topological Insulator Candidate EuIn$_2$As$_2$

Sabin Regmi·Md Mofazzel Hosen·Barun Ghosh·Bahadur Singh·Gyanendra Dhakal·Christopher Sims·Baokai Wang·Firoza Kabir·Klauss Dimitri·Yangyang Liu·Amit Agarwal·Hsin Lin·Dariusz Kaczorowski·Arun Bansil·Madhab Neupane

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Abstract

The higher order topological insulator (HOTI) has enticed enormous research interests owing to its novelty in supporting gapless states along the hinges of the crystal. Despite several theoretical predictions, enough experimental confirmation of HOTI state in crystalline solids is still lacking. It has been well known that interplay between topology and magnetism can give rise to various magnetic topological states including HOTI and Axion insulator states. Here using the high-resolution angle-resolved photoemission spectroscopy (ARPES) combined with the first-principles calculations, we report a systematic study on the electronic band topology across the magnetic phase transition in EuIn2As2 which possesses an antiferromagnetic ground state below 16 K. Antiferromagnetic EuIn2As2 has been predicted to host both the Axion insulator and HOTI phase. Our experimental results show the clear signature of the evolution of the topological state across the magnetic transition. Our study thus especially suited to understand the interaction of higher order topology with magnetism in materials.

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Sabin Regmi, Md Mofazzel Hosen, Barun Ghosh, Bahadur Singh, Gyanendra Dhakal, Christopher Sims, Baokai Wang, Firoza Kabir, Klauss Dimitri, Yangyang Liu, Amit Agarwal, Hsin Lin, Dariusz Kaczorowski, Arun Bansil, Madhab Neupane. 2019-11-09. Temperature Dependent Electronic Structure in a Higher Order Topological Insulator Candidate EuIn$_2$As$_2$. https://doi.org/10.1103/physrevb.102.165153

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